Omasum

Part of speech: noun

Pronunciation: /oʊˈmeɪsəm/

Definitions

1. A chamber in the digestive system of certain animals that helps process food through fermentation and nutrient uptake
2. A specialized compartment within the stomach of ruminant animals that plays a role in digesting and absorbing nutrients from ingested matter
3. A section of the stomach in some plant-eating mammals that aids in breaking down food and absorbing nutrients

Etymology: The third stomach of a ruminant, the one that bristles with leaf-like folds, takes its name from a Latin word meaning "tripe" or "bullock's paunch." Latin "omasum" is a learned borrowing, meaning English took the term directly from Latin rather than through everyday speech, which is typical of anatomical vocabulary. Its appeal to anatomists was the same as its appeal to cooks: the folds of the organ resemble the leaves of a book, and the animal's stomach was a familiar sight to anyone who butchered cattle. The word therefore names a feature that people had seen for centuries long before anyone needed a precise technical label for it. When anatomy became a formal science, Latin supplied the vocabulary, and "omasum" was adopted to distinguish this particular compartment from its neighbours, the rumen, reticulum and abomasum.